Photographic techniques are commonly used in the fabrication of printed circuits and other chemically-milled components to form images on the surfaces of rigid or flexible substrates such as circuit boards. Certain known circuit board configurations require formation of images on opposite sides of a common circuit board in close registration at critical locations such as at through holes, apertures, peripheral borders, and the like. For such circuit board configurations, it is common to expose both light-sensitive surfaces of the circuit board through respective image masters in order to improve productivity through subsequent photographic processes that develop and etch the final circuit patterns in close registration on the opposite sides of the circuit board.
Conventional fixtures for supporting image masters commonly rely upon composite materials that are less dimensionally stable than glass-based image masters, and thus such conventional fixtures suffer loss of registration accuracy attributable to wear, thermal variations, and the like.